Lucas Mast, 29

Lucas Mast went into a meeting with Wal-Mart executives last November armed with only a crude prototype of American Thunder, his idea for a lifestyle magazine geared to Nascar devotees. Fifteen minutes later, he left with a 1,800-store commitment.

So goes the success story of this lawyer turned telecom wonk turned magazine founder and editor in chief. Three issues later, American Thunder says it's shipping 200,000 copies to newsstands and 165,000 to subscribers.

"He located a niche and filled it in a fun, intelligent way," says Marianne Goldstein, executive director-editorial for United Feature Syndicate.

Mr. Mast at 29 now finds himself wrangling with magazine executives twice his age for ad dollars. "At first, I was selling the idea and not the product," he says. "It's just a matter of honing in on those advertisers."